Technical condition, indoor climate and renovation demand of brick apartment buildings in Estonia

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1 Technical condition, indoor climate and renovation demand of brick apartment buildings in Estonia Simo Ilomets Tallinn University of Technology, Estonia

2 Situation of housing in Estonia 71% of population lives in apartment buildings, 20%: in detached- or in terraced house, 9%: in farmhouses; Brick is one of the main structural material; Unknown Percentage of area of dwellings in apartmet buildings, % Today the end of the designed service life of these older buildings is close; Typically each occupant is owner of the apartment building; Milieu valuable areas (urban environment). 2

3 Service life of buildings / Performance criteria Service life Quality and properties of components and building materials; Design level; Work execution level; Indoor environment; Outdoor environment; In-use conditions; Maintenance level; Performance criteria: 7 essential requirements Mechanical resistance and stability; Safety in case of fire; Hygiene, safe to health and environment; Safety in use; Protection against noise; Energy performance Sustainable use of natural resources 3

4 The demand for renovation Typical aspects: 1. safety of building, durability; 2. healthy indoor climate; 3. energy performance + living & visual quality Renovation and reducing energy consumption of historical buildings need to be done without losing their cultural value and identity. Durability) Cultural value Cost 4

5 The areas of research Different areas of research Values: historical, cultural, architectural (milieu valuable areas); Structures: mechanical resistance and stability, durability, degradation of materials and components; Building physics, energy performance, indoor climate; Building services: heating, ventilation, water, sewerage, electricity, etc.; Background information of the building (actual drawings of the building; earlier damages, previous investigations, interviews, risk assessment); Scale of the research Case study (concerns one certain building or problem) Large scale study (concerns certain type of buildings or problems) 5

6 The aim of investigation Investigation of the degradations existents of the degradations extent of the degradations grade of the degradations Reasons of the degradations detection of faults in design and construction change of loading or alterations to a load-bearing member change in thermal or moisture conditions Renovation solutions Values; Structures; Building physics, energy performance, indoor climate; Building services. 6

7 Renovation demand of brick apartment buildings in Estonia National research project: Technical condition and service life of Estonian brick apartment buildings The main objectives: Survey of technical condition of typical brick apartment buildings; Investigate the indoor climate and energy performance of buildings; Determine the main demands of renovations of brick apartment buildings. Characterization of studied brick apartment buildings: 30 buildings, constructed between 1940 and 1990, 4-9 storey; From each building one to three apartments were selected to the indoor climate and building physics studies (50 apartments); All the buildings and apartments studied were in private ownership. The research was financed by Credit and Export Guarantee Fund KredEx and Tallinn University of Technology

8 Research Investigation of building envelope survey of technical condition of the structures (walls, floors, roofs, balconies) 8

9 Research Investigation of building envelope survey of technical condition of the structures (walls, floors, roofs, balconies) frost resistance of the facades 9

10 Research Investigation of building envelope survey of technical condition of the structures (walls, floors, roofs, balconies) frost resistance of the facades thermal transmittance and thermal bridges of building envelope FLIR Systems Sp1:temp C 5 air tightness of building envelope Sp2:temp -6.4 Sp3:temp

11 Research Investigation of building envelope; Indoor climate, hygrothermal conditions indoor temperature and RH over one year period at one hour interval indoor CO 2, performance of ventilation microbiological contamination on surfaces of building fabric and in indoor air

12 Research Investigation of building envelope; Indoor climate, hygrothermal conditions Conditions of building services FLIR Systems 27.8 C Sp3:temp 22.8 Sp1:temp Sp2:temp

13 Research Investigation of building envelope; Indoor climate, hygrothermal conditions Conditions of HVAC systems Measurement and simulation of energy use

14 Research Investigation of building envelope; Indoor climate, hygrothermal conditions Conditions of HVAC systems Measurement and simulation of energy use Questionnaire for occupants

15 The main problems in general Mechanical resistance and stability are not the main problems The main technical problems are in the field of: indoor climate, building physics, HVAC systems, energy efficiency. Old dwellings need improvement to meet today s requirements in a: healthy indoor climate, thermal comfort, energy performance, functional / architectural, structural / technical. Sound insulation insolation Environmental pollution Criminality Dampness Roof leakage Daylighting Stuffy air Sound insolation insulation Condensation on windows High temp. during summer Mold growth Low temp.' during winter Problem in housholds, % 67 Problem in housholds, %

16 The main needs for renovation Improvement of indoor climate and energy performance of buildings in cold climate: performance of building envelope; performance of ventilation; performance of heating systems. Building envelope Indoor climate; Energy perfornace Performance of ventilation Performance of heating system 16

17 Ventilation Typical problems of existing systems: natural ventilation (passive stack, window): low air change, low indoor air quality, high moisture load, no heat recovery: large energy consumption, impossible to regulate air flows, air inflow from stack (wind), air tightness of old ventilation channels, the replacement of windows without renovation of ventilation: smaller leakage rate, more airtight building envelope. Ventilation airflow, l/(s*pers) Air change rate in bedroom, 1/h New windows, no fresh air valves L avg =3,2 l/s New windows, no fresh air valves n avg =0,45 h -1 Old windows, L avg =3,2 l/s Old windows, n avg =0,90 h -1 17

18 Ventilation Challenges for renovation: mechanical exhaust ventilation with fresh air inlets: thermal comfort during winter (fresh air inlets with radiators) energy performance (exhaust air heat pump domestic hot water and heating) air tightness of old ventilation channels not suitable for combined ventilation channels 18

19 Ventilation Challenges for renovation: mechanical exhaust ventilation balanced ventilation with room units: where to put room units: a little space, problems with sound pressure levels, where to put air channels: rooms height 2.5m, air flow in apartment through existing doors 19

20 Ventilation Challenges for renovation: mechanical exhaust ventilation balanced ventilation with room units acceptance of occupants: how to motivate occupants for changes: I do not want new tubes and noisy equipment in my apartment renovation works in apartments, change of internal doors? cost-effective solutions are needed, understanding about the importance of ventilation (customer, occupants): example-renovation without changes in ventilation: bad indoor climate

21 Thermal envelope Existing problems: high thermal transmittance: external walls W/(m 2 K), roof-ceilings W/(m 2 K), windows 2 3 W/(m 2 K). 21

22 Thermal envelope Existing problems: high thermal transmittance serious thermal bridges: a large problem especially in old apartment buildings mould growth and surface condensation on the internal surfaces of thermal bridges is unavoidable without: - lowering thermal transmittance, - lowering internal humidity loads. 22

23 Existing problems: high thermal transmittance: serious thermal bridges: external walls W/(m 2 also roof-ceilings big problem in old apartment W/(m 2 buildings windows already additionally 2 3 W/(m 2 K). insulated (windows) low frost resistance: a need to protect facade, carbonization of mortar, it is economically reasonable to make the additional thermal insulation for walls and roofs (strong pressure). cultural value should be preserved Thermal envelope 23

24 Thermal envelope Internal thermal insulation is risky solution in cold climate: mould growth and condensation in the wall on the old wall surface Relative humidity, RH% Risk for mould growth Temperature t w, o C risk for mould t&rh in the wall 24

25 Thermal envelope Typical problems with the additional insulation: Windows: old or new, on its original place thermal bridge in connection of wall and window visually bad solution 25

26 Thermal envelope Typical problems with the additional insulation: Windows: old or new, on its original place Low quality: air space between old wall and new insulation; 26

27 Typical problems with the additional insulation: Thermal envelope Windows: old or new, on its original Low place quality: air space between old thermal wall and bridge new insulation; connection of Loggias: wall and thermal window bridges, mould visually bad solution 27

28 Typical problems with the additional insulation: Thermal envelope Windows: old or new, on its original Low place quality: air space between old thermal wall and bridge new insulation; connection of Loggias: wall and thermal window bridges, mould Drying visually out of bad structural solution moisture 28

29 Typical problems with the additional insulation: Thermal envelope Windows: old or new, on its original Low place quality: air space between old thermal wall and bridge new insulation; connection of Loggias: wall and thermal window bridges, mould Drying visually out of bad structural solution moisture Complex renovation (ventilation + building envelope + heating systems) is not common: mould after insulation (ventilation was not renovated) 29

30 Heating systems Typical solution: one-pipe heat distribution system; no room thermostats on radiators; Typical problems: incorrect control curve of the temperature of the supply water of the heating system, incorrect water flow rate of the risers of the heating system, lack of direct room temperature control, difficulties to balance the one-pipe heat distribution system, lack of maintenance and improper modifications of the heating and ventilation systems. 30

31 Conclusion There exists a demand to renovate brick apartment buildings: to lenghten the service life of building; to provide healthy indoor climate; to lower the energy consumption of buildings (pressure from occupants and from EU (20/20/20)); to ensure mechanical resistance and stability. During renovation of historical buildings we face different problems compared to new buildings; During renovation of historical buildings the identity should be preserved; There is a need for different renovation solutions where all presented aspects are taken into account; Example renovations with good practice, including monitoring and actual performance reports, are needed.